Collaborative Research: Allometry of Behavior in Spatially Patterned Resource Landscapes

Regents Of The University Of Idaho, Moscow ID

Investigators

Abstract

In natural ecosystems, resources are not uniformly available across space and time. Consequently, animals must adjust their behavior in response to changing environmental conditions to maximize survival and reproductive success. Theory holds that the ability to make such adjustments should be constrained by body size, because fundamental traits such as energy requirements are strongly influenced by size. Nevertheless, how body size limits animals' ability to respond to environmental variation remains poorly understood. This research will improve understanding of (a) how body size limits the range of behaviors available to animals for coping with environmental change or variation, and (b) how the distribution of resources such as food, concealment cover from predators, and favorable microclimates interacts with behavior to determine the success of individuals and populations that differ in body size. The project is based in Mozambique's Gorongosa National Park, which was devastated during civil war (1977-1992) and is being rehabilitated with assistance from USAID and other agencies, in light of recognition that stability in eastern Africa and cessation of the illegal ivory trade are vital to U.S. interests. Beyond this specific ecosystem, the study will yield generalizable insights that can inform the management and conservation of North American species with high recreational and economic value (e.g., deer, elk, and moose) that also span a range of body sizes. Finally, the project facilitates STEM training and education for U.S. students alongside Mozambican students in an international setting, which will contribute to the development of a diverse and globally engaged STEM workforce. Behavioral plasticity is constrained by morphology and physiology; because these often scale allometrically with body size, so should behavior. Indeed, the allometry of behavior is predicted to emerge from the interaction of (a) size-varying traits that influence animal performance (e.g., energy requirements), and (b) biotic and abiotic habitat attributes, such as the distribution of resources and microclimates. This project integrates observational, experimental, molecular, and modeling approaches to shed new light on the mechanisms that underpin animal behavior and population dynamics in an African savanna ecosystem that is both spatially and seasonally heterogeneous. The study system (Gorongosa National Park, Mozambique) is characterized by spatially patterned termite mounds that govern the distribution of vegetation, nutrients, and microclimates at broad spatial scales, and that are heavily used by three congeneric antelope species (bushbuck, nyala, and kudu, all Tragelaphus spp.) that vary five-fold in body size. This combination of factors presents an ideal opportunity to study the effects of body size and resource distribution on behavior and population dynamics. The unifying concepts of allometric scaling and resource heterogeneity mean that our insights will be generalizable and applicable across ecosystems, including to the management of North American wildlife populations. Broader impacts include development of an immersive, interdisciplinary field course offered to both U.S. and Mozambican students, broad public dissemination of research results via scientifically rigorous short films, and collaboration with park officials to develop effective wildlife-management policies.